from django.core.exceptions import ValidationError
from django.db import models

from accounts.models import DepotUser
from common.fields import ContainerNumberField, UpperCaseCharField
from common.models import ContainerTypeModel, LinesModel, OperationModel

# Create your models here.
class Booking(models.Model):

    STATUS_CHOICES = [
        ('active', 'Active'),
        ('finished', 'Finished'),
        ('canceled', 'Canceled'),
    ]

    number = UpperCaseCharField(max_length=50)
    vehicles = UpperCaseCharField(blank=True, null=True)
    container_type = models.ForeignKey(
        ContainerTypeModel,
        on_delete=models.CASCADE,
        related_name='booking_container_types',
    )
    container_count = models.PositiveIntegerField()
    container_expedited_count = models.PositiveIntegerField(default=0)
    carrier = models.CharField(max_length=100, blank=True, null=True)
    line = models.ForeignKey(
        LinesModel,
        on_delete=models.CASCADE,
        related_name='booking_lines',
    )
    visible = models.BooleanField(default=True)
    is_new = models.BooleanField(default=True)
    container_number = ContainerNumberField(max_length=11, blank=True, null=True)
    vehicles_left = models.CharField(blank=True, null=True)
    created_on = models.DateTimeField(auto_now_add=True)
    created_by = models.ForeignKey(DepotUser, related_name='booking_created_user', on_delete=models.CASCADE)
    updated_on = models.DateTimeField(auto_now=True)
    updated_by = models.ForeignKey(DepotUser, related_name='booking_updated_user', on_delete=models.CASCADE)
    status = models.CharField(
        max_length=10,
        choices=STATUS_CHOICES,
        default='active'
    )

    @property
    def containers_left(self):
        return self.container_count - (self.container_expedited_count or 0)

    class Meta:
        app_label = 'booking'

    def clean(self):
        if Booking.objects.filter(number=self.number, status='active').exclude(id=self.id).exists():
            raise ValidationError(f'Booking with number {self.number} already exists and is active.')